TWI606279B - Optical film and manufacturing method for the same - Google Patents

Description

Optical film and manufacturing method thereof

The present invention relates to an optical film and a method of manufacturing the same, and more particularly to an optical film for a display device and a method of fabricating the same.

Polarizers are widely used in optical components of liquid crystal displays. With the increasing use of liquid crystal displays, such as mobile phones and wearable devices, the requirements for the quality of polarizing plates are becoming higher and higher.

Polarizers are typically cut to fit to displays of various sizes. In addition, since the material size of various optical films differs greatly from the size required for the finished product, the optical film is also cut during the production of the polarizing plate to adjust the film size.

The present invention relates to an optical film and a method of manufacturing the same. Optical films have good optical properties.

According to one aspect of the invention, an optical film is provided that includes an optical layer and a protective film. The protective film comprises an adhesive layer and a protective layer. The protective layer is attached to one side of the optical layer by an adhesive layer. The width of the protective film is less than the width of the optical layer.

According to another aspect of the present invention, a method of fabricating an optical film is provided that includes a cutting step and a bonding step. The cutting step includes cutting both ends of a protective film in a width direction to cut an inner portion and an outer portion. The protective mucosa includes an adhesive layer and a protective layer. The bonding step includes attaching a protective layer of the inner portion to one side of the optical layer by an adhesive layer of the inner portion to form an optical film. The width of the inner portion of the protective film is less than the width of the optical layer.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below in detail as follows:

102‧‧‧Optical diaphragm

104‧‧‧Optical layer

106‧‧‧Adhesive layer

108‧‧‧Protective layer

110‧‧‧Protective mucosa

112‧‧‧Roller

IP‧‧‧Inside

K‧‧‧ cutting device

L1, L2, S1, S2‧‧‧ side

LD‧‧‧ length direction

OP1‧‧‧ first outer part

OP2‧‧‧ second outer part

W1, W2, W31, W32‧‧‧ width

WD‧‧‧Width direction

1 is a cross-sectional view of an optical film in accordance with an embodiment.

2 is a top view of an optical film in accordance with an embodiment.

FIG. 3 is a schematic view showing a method of manufacturing an optical film according to an embodiment.

Figure 4 is a cross-sectional view showing a protective mucosa according to an embodiment.

FIG. 5 is a schematic view showing the protective mucus in the cutting step in the manufacturing method according to an embodiment.

The embodiment of the disclosure proposes an optical film and a manufacturing method thereof, wherein the manufacturing method first cuts a protective layer having an adhesive layer and adhesion thereof, and then attaches the protective layer to the optical layer by an adhesive layer, thereby An optical film having stable and good properties is formed.

The following disclosures are not intended to illustrate all possible embodiments, and other embodiments not disclosed in this disclosure may be applied. Again, the map The size ratio on the scale is not drawn in proportion to the actual product. Therefore, the description and illustration are for illustrative purposes only and are not intended to be limiting. In addition, the description in the embodiments, such as the detailed structure, the process steps, the material application, and the like, are for illustrative purposes only and are not intended to limit the scope of the disclosure. The details of the steps and the details of the embodiments may be varied and modified in accordance with the needs of the actual application process without departing from the spirit and scope of the disclosure. The same/similar symbols are used to describe the same/similar elements.

1 is a cross-sectional view of an optical film 102 in accordance with an embodiment. The optical film 102 includes an optical layer 104 and a protective film 110 attached to one side of the optical layer 104. The protective film 110 includes an adhesive layer 106 and a protective layer 108. The protective layer 108 can be attached to the optical layer 104 by the adhesive layer 106. In the embodiment, the protective layer 108 has the same width W1 as the adhesive layer 106, and the width W1 is smaller than the width W2 of the optical layer 104. In the embodiment, the side edges S1 and S2 of the optical layer 104 and the side edges L1 and L2 of the protective film 110 do not overlap in the width direction WD. Further, as shown in FIG. 1, in the width direction WD, the side edges S1 and S2 of the optical layer 104 extend beyond the side edges L1 and L2 of the protective film 110, respectively. Thereby, in the process of bonding the protective film 110 to the optical layer 104, it is ensured that the adhesive layer 106 of the protective film 110 is effectively coated on the optical layer 104, so as to avoid the incomplete process due to incomplete bonding in the subsequent process. The situation in which bubbles occur.

In an embodiment, for example, the side S1 of the optical layer 104 beyond the side edge L1 of the protective film 110 and/or the side edge S2 of the optical layer 104 beyond the side edge L2 of the protective film 110 may occupy the width of the optical layer 104. 1% of W2 To 3%.

In one embodiment, the optical film 102 is a long strip film that can be wound up. As shown in the upper view of the optical film 102 of FIG. 2, the optical film 102 is a long strip-shaped layer film extending in the longitudinal direction LD (that is, the winding direction) of the vertical width direction WD. Thereby, the entire optical film 102 can be effectively processed by means of unwinding or winding.

Referring to FIG. 1, for example, the optical film 102 may be a polarizing plate. The optical layer 104 may be a polarizer for converting light passing through the optical layer 104 (polarized light having any direction) into polarized light of a specific direction. The material of the polarizer may be a polyvinyl alcohol (PVA) resin film which can be obtained by saponifying polyvinyl acetate resin. Examples of the polyvinyl acetate resin include a single polymer of vinyl acetate, that is, polyvinyl acetate, and a copolymer of vinyl acetate and other monomers copolymerizable with vinyl acetate. Other examples of monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids (e.g., acrylic acid, methacrylic acid, ethyl acrylate, n-propyl acrylate, methyl methacrylate), olefins (e.g., ethylene, propylene, 1). -butene, 2-propene), vinyl ether (such as ethyl vinyl ether, methyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether), unsaturated sulfonic acid (such as vinyl sulfonic acid, vinyl) Sodium sulfonate) and so on.

In an embodiment, the optical layer 104 can be a single layer structure or a multilayer structure. In other words, the optical layer 104 may be a single layer structure of the polarizer; or the optical layer 104 may further include at least one protective film (eg, cellulose triacetate) disposed on at least one side of the polarizer for Protecting and supporting the polarizer; or the optical layer 104 may further include other optical films, such as a retardation film, an anti-reflection film, an anti-glare film, etc., disposed on the polarizer One side is less, so that the optical film 102 has the above characteristics.

In an embodiment, the protective layer 108 may be a single layer or a multilayer structure, and the material thereof may be selected from the group consisting of polymethylmethacrylate (PMMA), Triacetyl Cellulose (TAC), acrylic resin film, and poly Aromatic hydroxy resin film, polyether resin film, cyclic polyolefin resin film (for example, polybornene resin film), polyester (Polyethylene Terephthalate, PET), polypropylene (PP), cycloolefin polymer (Cyclo Olefin Polymer, COP), Polycarbonate (PC), and a group of any combination of the above.

In an embodiment, the protective mucosa 110 is selectively detachable from the optical layer 104. In other words, the protective layer 108 and the adhesive layer 106 are selectively removable from the optical layer 104. In an embodiment, the protective film 110 may be a surface protective film for protecting the optical layer 104, thereby preventing the optical layer 104 from being damaged during subsequent processes or transportation. When the optical film 102 (for example, a polarizing plate) is to be attached to a display device (for example, a display panel, glasses, or the like), the protective film 110 can be peeled off.

FIG. 3 is a schematic view showing a method of manufacturing the optical film 102 according to an embodiment. The protective film 110 as shown in FIG. 4 can be transferred through the roller 112 or other suitable device, including the (uncut) protective layer 108 and the adhesive layer 106 adhered to the protective layer 108. In one embodiment, the width of the protective film 110 may be close to the width W2 of the optical layer 104 (FIG. 1), but the disclosure is not limited thereto.

Referring to FIGS. 3 and 5 simultaneously, in the manufacturing method according to an embodiment, the protective film 110 is cut in the cutting step, and the protective film 110 is transported through the cutting device K in the longitudinal direction to the width direction. The inner side portion IP, the first outer side portion OP1 and the second outer side portion OP2 are cut out at both ends of the protective film 110 on the WD. In the embodiment, the first outer portion OP1 and the second outer portion OP2 are opposite end portions of the protective film 110 in the width direction WD. In one embodiment, only one end of the protective film 110 may be cut in the width direction WD according to product design or process requirements.

Then, as shown in FIG. 3, the inner portion IP obtained by the cutting step can be conveyed and further pressed by the roller 112 to form an optical film 102 as shown in FIG. The first outer portion OP1 and the second outer portion OP2 obtained by the cutting step can be retracted by a roller (not shown) to convey a route away from the inner portion IP.

Referring to FIG. 5, in the cutting step, the cutting position of the protective film K in the width direction WD of the protective film K can be determined by the effective width of the adhesive layer 106 to ensure that the adhesive layer 106 of the inner portion IP is effective. The protective layer 108 is coated (ie, not left blank). The cutting device K may include a cutter, a circular knife, a knife blade, a laser cutter, an ultrasonic cutter, and the like.

Specifically, in the process of generally forming the protective film 110, the adhesive layer 106 is mainly applied in an intermediate portion of the protective layer 108 in the width direction WD with an effective width, and the opposite end portions may not be coated. Adhesive layer 106 (so-called white space). When the protective film 110 is not subjected to the cutting step and the protective layer 108 is directly bonded to the optical layer 104 by the adhesive layer 106, the white portion is likely to cause bubbles in the width direction WD to affect the properties of the optical film.

In this embodiment, the first outer portion OP1 and the second outer portion OP2 (Fig. 5) which may not be applied to the adhesive layer 106 are removed by a cutting step, leaving The lower adhesive layer 106 is effectively coated with the inner portion IP of the protective layer 108 to continue the transfer, and is bonded to the optical layer 104 to form the optical film 102 (Fig. 1 and Fig. 3). Since the protective layer 108 of the inner portion IP has no white portion which is not coated by the adhesive layer 106, the problem of the generation of bubbles in the optical film 102 can be avoided while maintaining the desired quality.

Referring to FIG. 5, in the embodiment, for example, the width W31 of the first outer portion OP1, the width W32 of the second outer portion OP2, or the width W31 of the first outer portion OP1 and the width W32 of the second outer portion OP2 The sum is 1% to 3% of the width of the protective film 110 (that is, the width W31 of the first outer portion OP1 and the width W32 of the second outer portion OP2 and the width W1 of the inner portion IP).

In some embodiments, for example, the width of the protective film 110 width depends on the size of the optical film 102, which may be 1490 mm (mm), 1540 mm, 1980 mm, etc., and the width W31 and the second outer portion of the first outer portion OP1. The width W32 of the OP2 can be independently 15mm to 20mm. However, the disclosure is not limited to this. The width W31 of the first outer side portion OP1 and the width W32 of the second outer side portion OP2 may be the same or different.

Referring to FIG. 5 , in the embodiment, for example, the cutting device K is a cutting device that can move in the width direction WD. Therefore, the cutting position can be arbitrarily adjusted according to actual needs, and the operation is convenient and flexible.

In some examples, after the protective mucosa 110 (Fig. 5) is cut by the cutting step, the inner portion IP is first wound into a roll for use, and when the inner portion IP is to be attached to the optical layer 104, The process is rolled up and then attached. Compared with the discontinuity of the inner portion IP by rewinding and re-opening The process, as shown in Figure 3, the cutting process and the continuous process of the bonding step can save man-hours (saving the process time of the inner part IP being wound up and unwinding), and also avoiding the inner part IP in the roll The quality of the optical film 102 can be improved by collecting, unwinding or storing the defects such as dust, contaminants and the like which are generated during standby.

The disclosure is not limited to the optical film 102 of the above three-layer structure and its manufacture. In other embodiments, the concept of the present disclosure may also extend to the fact that the optical film comprises a five-layer structure in which a release film is attached to the upper and lower sides of the optical layer by another adhesive layer, and the width of the release film is smaller than The width of the optical layer.

In an embodiment, the optical film may include optical layers of other structural types, such as optical gain, alignment, compensation, steering, orthogonal, diffusion, protection, anti-stick, scratch resistance, anti-glare, and reflection suppression. A layer having a high refractive index and the like may be, for example, an alignment liquid crystal layer having characteristics such as control of viewing angle compensation or birefracting, an easy-bonding treatment layer, a hard coat layer, an anti-reflection layer, an anti-adhesion layer, and diffusion. Various surface treatment layers such as layers and anti-glare layers.

According to the above, the manufacturing method in the embodiment cuts the outer portions of the opposite ends of the protective film, leaving the inner portion further adhered to the optical layer, thereby preventing bubbles from occurring in the optical film, and making the optical film excellent. Optical properties. The cutting device is a cutting device that can move along the width direction of the protective film, and is convenient to operate and has high elasticity. In addition, the optical film can be formed by a continuous process for the cutting step and the bonding step, which can save man-hours and avoid defects, thereby improving the quality of the optical film.

In summary, although the invention has been disclosed in the preferred embodiments, However, it is not intended to limit the invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

102‧‧‧Optical diaphragm

104‧‧‧Optical layer

106‧‧‧Adhesive layer

108‧‧‧Protective layer

110‧‧‧Protective mucosa

L1, L2, S1, S2‧‧‧ side

LD‧‧‧ length direction

W1, W2‧‧‧ width

WD‧‧‧Width direction

Claims (9)

An optical film comprising: an optical layer; and a protective film comprising: an adhesive layer; and a protective layer; wherein the protective layer is attached to one side of the optical layer by the adhesive layer; wherein the protective film The width of the optical layer is less than the width of the optical layer, and the width of one side of the optical layer beyond the side of the protective film is 15-20 mm in a width direction. The optical film of claim 1, wherein the protective layer has the same width as the adhesive layer. The optical film of claim 1, wherein in the width direction, the width of the side of the optical layer beyond the side of the protective film accounts for 1% to 3 of the width of the optical layer. %. The optical film of claim 1, wherein the optical layer comprises a polarizer. The optical film of claim 1, wherein the optical film is a rollable film, and the winding direction is perpendicular to the width direction. A method of manufacturing an optical film, comprising: a cutting step, comprising: Cutting a protective film in a width direction to cut an inner portion and an outer portion, wherein the protective film comprises an adhesive layer and a protective layer, and the outer portion of the protective film covers the protective film 1% to 3% of the width, and/or the width of the outer portion of the protective film is 15 to 20 mm; and a fitting step comprising: the inner portion of the inner portion A protective layer is attached to one side of an optical layer to form the optical film, wherein the inner portion of the protective film has a width that is less than a width of the optical layer. The method of manufacturing an optical film according to claim 6, wherein the cutting step and the bonding step are a continuous process. The manufacturing method of the optical film of claim 6, wherein the cutting step comprises: cutting the protective film in the width direction through a movable cutting device to cut the inner portion With the outer part. The manufacturing method of the optical film of claim 8, wherein the cutting step further comprises: conveying the protective film along one of the length directions perpendicular to the width direction; and moving the cutting device in the width direction The protective mucosa is cut.